In an email sent to Google Mobile Services partners on October 5th, Google outlined a significant change to the core GMS package (AKA gapps) for telephony-enabled Android devices (basically, smartphones). As of December 1st, Google will no longer require Hangouts to be bundled with new hardware. An excerpt of that email follows.

Today, we are announcing that Google Duo will replace Hangouts within the suite of core GMS apps, and Hangouts will become GMS Optional for telephony products. This change will take effect on December 1, 2016.

This does not mean Hangouts, or Hangouts for Android, is dead. It does mean that manufacturers may opt to stop including it on smartphones released in 2017, so you'd have to download it from the Play Store after initial setup.